血管内皮细胞生长因子在法医学中的应用

血管内皮细胞生长因子(VEGF)是损伤愈合过程中启动血管形成的一个特异的有丝分裂原,也是一种有效的血管通透性诱导因子。本文结合有关文献,对当前有关的VEGF分子生物学特性,VEGF与损伤修复的关系及表达规律等方面的研究现状作一简要综述。     

脑干损伤后神经元及轴突改变的组织化学观察

采用针刺法造成大鼠脑干损伤,用尼氏体染色、嗜银染色和改良三色法观察脑干神经元及轴突在伤后不同时间的病理改变。结果发现,嗜银染色显示伤后 1～ 3h部分神经纤维不规则增粗、少数断裂, 6h断端膨大呈球形, 15h收缩球较为明显,至 24h收缩球明显且数量增多;改良三色法显示伤后 3～ 6h部分髓鞘与轴突之间的间隙增宽, 15h髓鞘明显弯曲、不完全地附着在轴突表面,甚至剥脱,持续到伤后 24h;尼氏体染色显示神经元核周尼氏体在伤后 24h减少。该结果提示,组织化学染色能观察到脑干损伤后的病理改变,并且有可能用于推断脑干损伤时间。     

实验性脑挫伤后 Fos蛋白和 NGFR变化与损伤时间关系的研究

目的 检测分析不同损伤时间组实验大鼠脑挫伤灶周围神经细胞中 NGFR阳性染色强度变化与损伤后经过时间之间的关系,对其在脑挫伤时间推断中的作用作出评价。方法 运用免疫组织化学技术（ SABC法）,结合计算机彩色图像分析技术观察大鼠实验性脑挫伤后原癌基因 c－ fos的表达产物 Fos蛋白和神经生长因子受体（ NGFR）的染色变化。结果 （ 1）伤后 0.5h组在挫伤灶周围可见 Fos阳性染色细胞出现。伤后 3h组阳性表达数量和强度达峰值,且分布广泛。后表达逐渐降低。 1d后各组未见 Fos阳性染色强度增加的细胞。对照组染色为阴性。（ 2）伤后 1d组在挫伤灶周围可见少量 NGFR阳性染色细胞,以神经细胞表达为主。伤后 3d组,阳性细胞表达与 1d组相比有显著性增强 (P< 0.01), 数 量 和 着 色 强 度 达 到 高 峰 , 量 多 且 染 色 深 。 之 后 逐 渐 缓 慢 减 弱 。 对 照 组 染 色 为 阴 性 。 可 见 脑 挫 伤 后 Fos和 NGFR在 损 伤 局 部 的 阳 性 染 色 分 别 在 伤 后 早 期 及 随 后 较 晚 时 段 里 出 现 。 前 者 表 达 时 间 短 暂 , 而 后 者 则 持 续 时 间 较 长 , 但 都 有 一 定 的 规 律 性 。 结 论 Fos蛋 白 和 NGFR变 化 可 用 于 脑 挫 伤 后 不 同 时 段 的 损 伤 时 间 推 断 。     

电击伤组织的超微结构观察

目的 观察电流传导路径上器官、组织的超微结构变化。 方法 对 SD大鼠进行实验性低电压电击。结果 触电部位皮肤的上皮细胞胞浆内基质凝固、膜系统断碎;骨骼肌肌小节出现异常收缩带;心肌的变化也较明显,可见局灶性溶解坏死并出现异常收缩带;电流传导路径上外周血管、神经的改变以血管明显,血管内皮细胞胞浆中出现空泡,中膜平滑肌可见溶解坏死,神经纤维仅见部分髓鞘松解。 结论 电击伤组织的超微结构变化可作为诊断电击死组织学变化的补充,为解决无明显皮肤电损伤的电击死案件提供形态学指标。同时也探讨了电击伤超微结构变化的形成机制。     

Stature estimation from radiographically determined long bone length in a Spanish population sample

The estimation of stature from of a variety of bones is an important aspect of forensic work. In order to obtain reliable results, it is important to have comparative data obtained from the same population group as the skeletal remains. However, lack of up to date information on the population groups of Southern Europe makes the estimation of stature from bones in this area subject to possible error. In this study, the stature of 104 healthy adults from Spain was measured, and an anteroposterior teleradiograph of the right lower and the right upper limb of every subject in the study was made in order to measure the lengths of the femur, tibia, fibula, humerus, cubitus and ulna. Pearson's regression formulae were obtained for both limbs. In males, we found the femur to be the most accurate predictor of stature (R = 0.851), whereas in females best results were obtained with the tibia (R = 0.876).     

Seasonality of insect succession and pig carcass decomposition in a natural forest area in southeastern Brazil

In this study, successional patterns, relative abundance of larvae and adults of sarcosaprophagous insects, carcass decay, diversity and seasonality of species, and their potential as forensic indicators were studied. Four experiments were carried out in each season in a natural area of southeastern Brazil. Two pigs (Sus scrofa L.) were used in each experiment and were exposed to sunlight and shade, respectively. The Calliphoridae outnumbered the Sarcophagidae in specimens collected and reared from the carcasses. More insects were collected from carcasses exposed to the sun, while a larger number of specimens were reared from those in the shade. Temperature and rainfall influenced the stages of carcass decay and insect activity and abundance. Chrysomya albiceps was the most abundant species in all four experiments. The carcasses were used as a protein source and substratum for oviposition. The dark putrefaction and fermentation stages yielded more flies than the other stages. These results show that flies are important in carcass decay and are, therefore, also of forensic importance. Seven species can be considered valuable forensic indicators in Southeastern Brazil. However, only three species were useful as forensic indicators in wooded areas: P. intermutans, H. segmentaria, and H. semidiaphana.